From patchwork Thu Mar 21 16:57:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 13599256 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6E486CD11DC for ; Thu, 21 Mar 2024 16:58:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uimLG4qtyoWC+/FlCJp+MrAnTRtX/YVnPcc9+42d6lI=; b=xtoWLgWrIbF3C1 81Q8u8zHdksZHNRTnUdD0JRlrQo3mmZzbxelMdL0xSAwmzAO7QYlK3bW5Ni3xFKmTGwadbwPNgILN 3ojuLl/KDn5qxS/cROzqGqjRIUWEw4reW60TC1lCvAvgkvpCbCbqlyAj8ytq7GXX5lJ9URa+/5pgc dVjgJekS4etlr4ZGzomSNjA++uJ1oKgK2soRG5q3oUW6X6N9fill9O4qkZHyRCIpwpcnp3PgGOoVf 34Md/ceNnHgbNw7Q/xCtOhbmpZd53hGs6HKC1u9m6mbzMK4ztUPijaz/zTrvo8qQyOOdPc1ja0DNW 5YQamyYloWjUJZdds4CQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rnLjt-00000003xAZ-0kZz; Thu, 21 Mar 2024 16:58:01 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rnLjm-00000003x4W-1Upt for linux-arm-kernel@lists.infradead.org; Thu, 21 Mar 2024 16:57:55 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id ECC2D1007; Thu, 21 Mar 2024 09:58:26 -0700 (PDT) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5C3A83F67D; Thu, 21 Mar 2024 09:57:51 -0700 (PDT) From: James Morse To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Cc: Marc Zyngier , Oliver Upton , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Jing Zhang , James Morse Subject: [PATCH v3 6/6] KVM: arm64: selftests: Test ID_AA64PFR0.MPAM isn't completely ignored Date: Thu, 21 Mar 2024 16:57:28 +0000 Message-Id: <20240321165728.31907-7-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20240321165728.31907-1-james.morse@arm.com> References: <20240321165728.31907-1-james.morse@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240321_095754_546097_66469ED8 X-CRM114-Status: GOOD ( 16.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The ID_AA64PFR0.MPAM bit was previously accidentally exposed to guests, and is ignored by KVM. KVM will always present the guest with 0 here, and trap the MPAM system registers to inject an undef. But, this vaulue is still needed to prevent migration when the value is incompatible with the target hardware. Add a kvm unit test to try and write multiple values to ID_AA64PFR0.MPAM. Only the hardware value previously exposed should be ignored, all other values should be rejected. Signed-off-by: James Morse --- .../selftests/kvm/aarch64/set_id_regs.c | 53 ++++++++++++++++++- 1 file changed, 52 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/aarch64/set_id_regs.c b/tools/testing/selftests/kvm/aarch64/set_id_regs.c index b42a0dc19852..fbb600111969 100644 --- a/tools/testing/selftests/kvm/aarch64/set_id_regs.c +++ b/tools/testing/selftests/kvm/aarch64/set_id_regs.c @@ -426,6 +426,56 @@ static void test_user_set_reg(struct kvm_vcpu *vcpu, bool aarch64_only) } } +#define MPAM_IDREG_TEST 1 +static void test_user_set_mpam_reg(struct kvm_vcpu *vcpu) +{ + uint64_t masks[KVM_ARM_FEATURE_ID_RANGE_SIZE]; + struct reg_mask_range range = { + .addr = (__u64)masks, + }; + uint64_t val, ftr_mask; + int idx, err; + + /* + * If ID_AA64PFR0.MPAM is _not_ officially modifiable and is zero, + * check that if it can be set to 1, (i.e. it is supported by the + * hardware), that it can't be set to other values. + */ + + /* Get writable masks for feature ID registers */ + memset(range.reserved, 0, sizeof(range.reserved)); + vm_ioctl(vcpu->vm, KVM_ARM_GET_REG_WRITABLE_MASKS, &range); + + /* Writeable? Nothing to test! */ + idx = sys_reg_to_idx(SYS_ID_AA64PFR0_EL1); + ftr_mask = ID_AA64PFR0_EL1_MPAM_MASK; + if ((masks[idx] & ftr_mask) == ftr_mask) { + ksft_test_result_skip("ID_AA64PFR0.MPAM is officially writable, nothing to test\n"); + return; + } + + /* Get the id register value */ + vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1), &val); + + /* Try to set MPAM=1 */ + val &= ~GENMASK_ULL(44, 40); + val |= FIELD_PREP(GENMASK_ULL(44, 40), 1); + err = __vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1), val); + if (err) { + ksft_test_result_skip("ID_AA64PFR0.MPAM is not writable, nothing to test\n"); + return; + } + + /* Try to set MPAM=2 */ + val &= ~GENMASK_ULL(43, 40); + val |= FIELD_PREP(GENMASK_ULL(43, 40), 2); + err = __vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1), val); + if (err == -EPERM) + ksft_test_result_pass("ID_AA64PFR0_EL1.MPAM not arbitrarily modifiable\n"); + else + ksft_test_result_fail("ID_AA64PFR0_EL1.MPAM value should not be ignored\n"); +} + static void test_guest_reg_read(struct kvm_vcpu *vcpu) { bool done = false; @@ -477,12 +527,13 @@ int main(void) ARRAY_SIZE(ftr_id_aa64isar2_el1) + ARRAY_SIZE(ftr_id_aa64pfr0_el1) + ARRAY_SIZE(ftr_id_aa64mmfr0_el1) + ARRAY_SIZE(ftr_id_aa64mmfr1_el1) + ARRAY_SIZE(ftr_id_aa64mmfr2_el1) + ARRAY_SIZE(ftr_id_aa64zfr0_el1) - - ARRAY_SIZE(test_regs); + ARRAY_SIZE(test_regs) + MPAM_IDREG_TEST; ksft_set_plan(ftr_cnt); test_user_set_reg(vcpu, aarch64_only); test_guest_reg_read(vcpu); + test_user_set_mpam_reg(vcpu); kvm_vm_free(vm);